Subset sum related problem

This is not a java related question, but i think it could be interesting to some of you guys. I appreciate if someone has more info about this. I have encountered a problem in my current project that seems pretty much related to the subset sum problem. I just want to make sure it is not a special case of the subset sum problem and whether it has a efficient solution or not. We are doing an application for tellers in a bank. The teller basically has a cash box that contains money of different denominations. He wants us to provide a function that assists him in determining whether his cashbox contains any collection of coins and notes that sum up to certain value or not. That is, he wants to ask, can I get 123.25 out of my cashbox? a typical cashbox will look like the illustrated figure. It seems to me a typical subset problem. The guy in the team who was doing this function came up with greedy algorithm and I showed to him that it is not always correct for the showed coin system . Yet, I am not quite sure if there are some special cases in this problem or not. ---------------------------------------------------------------- Avail. No. In Cashbox Denomination Value Total ---------------------------------------------------------------- 100 500 50,000<-- Notes 40 200 8,000 10 100 1,000 100 50 5,000 100 20 2,000 44 10 440 20 5 100 100 1 100 100 1 100 <--Coins 100 0.5 50 100 0.25 25 100 0.1 10 100 0.05 5 100 0.01 1